BEIRUT — Heavy government shelling of rebel positions near the Syrian capital killed 16 people today, activists said, as U.S. Secretary of State John Kerry lobbied European allies to back Washington’s proposed military action against the ruling regime.

The Britain-based Syrian Observatory for Human Rights said the mortar and artillery fire on the Moldokhiya agricultural area south of Damascus killed 14 rebels. Two civilians, including a child, also died in the shelling, it added.

The group also reported heavy fighting between rebels and troops loyal to President Bashar Assad around the Christian village of Maaloula. The rebel advance into the area that began on Monday was reportedly spearheaded by al-Qaida-linked fighters, exacerbating fears among Syrians and religious minorities in particular that Islamic extremists are playing an increasingly important role in the rebellion.

Fighters from the Western-backed Free Syrian Army have also participated in battles around Maaloula, destroying two government checkpoints near the town earlier this week, according to a statement by the main opposition coalition on Friday.

Kerry was in Lithuania to meet with European foreign ministers today.

European officials have been skeptical about whether any military action against Assad’s regime can be effective. Skeptical European foreign ministers today urged the U.S. to delay possible military action until U.N. inspectors report back.

Kerry said he would share their concern with Obama administration officials. A senior State Department official who attended Kerry’s meeting with the ministers in Lithuania said Kerry made clear that the U.S. has not made any decision to wait.

The U.N. inspectors’ report is expected later this month, although some European officials are asking the U.N. to speed up the probe or issue an interim report.

The prospect of a U.S.-led strike against Syria has raised concerns of potential retaliation from the Assad regime or its allies. On Friday, The State Department ordered nonessential U.S. diplomats to leave Lebanon over security concerns and urged private American citizens to depart as well.

The Shiite militant group Hezbollah, an Assad ally that has sent fighters into Syria, is based in Lebanon.

Syrian officials have been trying to capitalize on reluctance in Europe and the U.S., and both the government and state media accuse Obama of “supporting terrorism.”

“Any U.S. aggression against Syria has no explanation other than (that it’s) supporting terrorism,” Syrian Deputy Foreign Minister Faisal Mekdad said in an interview with state-run Al-Ikhbariya TV broadcast late Friday. He challenged international community to present evidence that Syria had used sarin, and said military action against his country would be “dangerous and might affect America’s friends and the entire world.”